Variable-exhaust pipe



UNITED STATES PATENT OEETOE.

WILLIAM P. PARROTT AND STEPHN. H. HEAD, OF BOSTON, MASSACHUSETTS.

VARIABLE-EXHAUST PIPE.

Specification of Letters Patent No. 22,819, dated February l, 1859.

T 0 all 'whom it may concern:

Be it known that we, VM. P. PARRo'r'r and S. H. HEAD, both of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Contracting Orifices of Blast-Pipes in Locomotive and other Furnaces, of which the following is a full, clear, and exact description, reference being had to the annexed drawings, making part of this specification, in which-w Figure l, is a longitudinal vertical section through the middle of the pipe, nozzle, and orifice; Fig. 2, a plan of the end of the nozzle with the cap removed; Fig. 3, a plan of the cap which covers the end of the nozzle, with the orice at full size; Fig. 4, a plan of the same with the orifice contracted.

It is found desirable to place the regulation of the orifice of the blast pipe of locomotive and other furnaces under the control of the engineer, this we have been enabled to do by the contracting nozzle which is the subject of this present invention.

To enable others skilled in the art to understand and use our invention, we will proceed to describe the manner in which we have carried out the same.

A, is the blast pipe to which is attached a nozzle B on the top of which are cut the dove-tail grooves a.

C, is a tube formed of strips or sections b, made of thin steel or other elastic material. The edges of these sections over-lap each other as seen in Fig. 3. They are held together and secured Within the nozzle B, by a ring c, and screws e, one to each section passing through the ring and through each section into the nozzle B. This arrangement while it holds the sections together and forms a perfect pipe, yet allows the upper ends of the sections to slide one within the other as the orifice of the pipe is contracted into the form shown dotted in Fig. l.

D, is a cap which fits over the end of the nozzle B, and is secured thereto by screws (l, which enter the groove f, cut around the outer surface of the nozzle allowing the cap to turn freely. This cap is moved by any suitable arrangement. In the drawings we have represented it as furnished with a gear cut on its outer edge to be operated by a worm on a rod the crank or handle of which is placed within reach of the engineer. The inner edge of this cap is cut in sections of the form represented in Figs. 3 and et, these sections 71., being segments of circles eccentric with the cap. This gives to the edge a cam like bearing against the blocks y. These blocks slide in the dovetail grooves a, in the top of the nozzle, into which theyY are inserted before the cap is put on. An end View of one of 'these blocks in its groove is shown dotted in Fig. l. One end of the block bears against the inner edge of the cap while the other presses against the sections of the pipe C at or near the place where they overlap each other.

The operation of our improved orifice is as follows: The cap D, being turned in the direction of the arrow Fig. 3, its inne-r edge it bearing against the block g, presses the upper ends of the segments of the pipe C. in toward its center, and as the edges of these segments slide one within the other the orifice is gradually contracted into the form shown in Fig. 4t. lWhen the cap is turned in the opposite direction as indicated by the arrow Fig. 4 the form of the edge z., allows the spring of the metal of which the sections of C, are composed, to force back the block f/vexpanding the orifice as required.

This arrangement when used on locomotives gives the engineer great control over his fire enabling him by enlarging or contracting the orifice of his exhaust pipe to urge his fire or not he may find expedient.

l/Vhat we claim as our invenion and desire to secure by Letters Patent, is

The within described contracting orifice for blast pipes constructed and operating in the maner and for the purpose substantially as herein set forth.

In testimony whereof witness our signatures this 3d day of September A. D. 1856.

lVM. P. PARRIOTT. STEPHEN H. HEAD. In presence of- JOHN S. CLow, THos. R. RoAcH. 

